[Preoperative chemoradiotherapy with S-1 for advanced low rectal cancer]

We reviewed the patients with neoadjuvant chemoradiotherapy (CRT) with S-1 to evaluate the feasibility and effectiveness for locally advanced lower rectal cancer. The CRT regimen consisted of pelvic irradiation (45 Gy in fractions of 1.8 Gy), five days a week. A treatment of oral S-1 (80 mg/m2 per day) on days 1-14 and 22-35 was given during radiotherapy. Patients underwent a curative resection with lateral lymph node resection at 6-8 weeks intervals after neoadjuvant CRT. The response rate on pathological study was 60% (all were grade 2), and no patients had lateral lymph node metastases. Grade 1 or 2 adverse effects occurred in all patients during CRT, but the CRT was achieved in all patients. We found two patients had surgical complications with wound infection and one patient with anastomotic leakage. All complications were improved by conservative treatment. The neoadjuvant CRT was feasible and effective treatment for all patients with locally advanced rectal cancer. We have started a phase II study of the neoadjuvant CRT.